Windshield wiper drive apparatus



Nova Ill, 1952 c, p, MQCLELLAND 2,617,335

WINDSHIELD WIPER DRIVE APPARATUS Filed June 29, 1951 r Y 2 SHEETS-SHEET1 J2 I I a 14 55 1.9 66 J/- 674 if a; 24 I I 535 v"uulnnhununu mu is 17k Quanta C/arekzce WW: Kiel/and v attorneys Nov 11, 5 c. P. M CLELLANDWINDSHIELD WIPE-R DRIVE APPARATUS 2 SHEETS-SHEET 2 Filed Jurie 29, 1951mm m. a

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/ (Ittqrnegs Patented Nov. 11, 1952 WINDSHIELD WIPER DRIVE APPARATUSClarence P. McClelland, Royal Oak, Mich, as-

signor to General Motors Corporation, Detroit, Mich., a corporation ofDelaware Application June 29, 1951, Serial No. 234,241

11 Claims. 1

This invention relates to windshield wiper drive apparatus, and moreparticularly to improved operating means on the wiper motor drive shaft.

One feature of the invention is that it provides improved windshieldwiper drive apparatus; another feature of the invention is that itprovides drive apparatus comprising a plurality of pulleys mounted onthe windshield wiper motor drive shaft; a further feature of theinvention is that spring means are provided interconnecting certain ofsaid pulleys for causing relative rotation therebetween to tighten thewindshield wiper cables; and yet another feature of the invention isthat readily releasable means are provided for locking the pulleys tothe drive shaft to hold the cables taut.

Other features and advantages of the invention will be apparent from thefollowing description and from the drawings, in which:

Fig. 1 is a fragmentary elevational view of a portion of the dash paneland windshield of an automobile, parts being broken away to show theimproved windshield wiper drive apparatus; Fig. 2 is an enlargedfragmentary section taken along the line 2-2 of Fig. 1; Fig. 3 is afurther enlarged fragmentary section taken along the line 3-3 of Fig. 2;Fig. 4 is a transverse section taken along the line 4-4 of Fig. 3; Fig.5 is a transverse section taken along the line 55 of Fig. 3; Fig. 6 is atransverse section, partly broken away, taken along the line 68 of Fig.3, and looking in a direction opposite to that of Fig. 5; and Fig. '7 isa fragmentary section through a modified form of apparatus incorporatingthe invention.

In an automobile a Windshield wiper is usually provided at each side ofthe vertical center line of the windshield, one wiper being in front ofthe drivers seat and the other Wiper being in front of the passengersseat. Both of these wipers usually are operated by means of a singlemotor positioned forwardly of the fire Wall adjacent the longitudinalcenter line of the automobile, said motor having a drive shaft whichprojects rearwardly through the fire Wall and which is connected bymeans of flexible cables to left and right output. shafts upon which therespective wipers are mounted, the cables extending between the driveshaft and the respective output shafts.

The flexible cables are conventionally secured to the respective outputshafts by means of pulleys mounted on the output shafts, and the cablesin the past have usually been secured to the primary or motor driveshaft by means of arms extending radially from the drive shaft. In orderto operate the wipers the drive shaft is rocked or oscillated by themotor, the flexible cables transmitting this oscillatory motion tothe'respective output shafts for operating the wipers. In this type ofconstruction the flexible cables move bodily in directions transverse oftheir length as the rocker arms oscillate about the axis of the driveshaft. This transverse movement of the cables made it necessary,particularly near the longitudinal center of the automobile where thecables connect with the ends of the rocker arms, to provide free spaceto accommodate the movement, thus limiting the remaining space availablefor other elements such as the radio, glove compartment, etc.

According to the present invention the cables are affixed to pulleys onthe drive shaft, and the only movement of the cables is in directionslongitudinal thereof. Since the cables do not move bodily in directionstransverse of their length, it is not necessary to provide any freespace adjacent the cables, and the space available for other elements isincreased.

In order to install the cables and other windshield wiper operatingapparatus it is desirable that the cables have some play so that theparts may be properly positioned. However, once the apparatus isinstalled it is necessary that the cables be taut in order that powerfrom the motor may efficiently be transmitted to the Wiper operatingshafts.

In my co-pending application for Windshield Wiper Drive Apparatus, filedNovember 17, 1950,

as S. N. 195,268, I disclosed improved cable ten- 7 sioning apparatuscomprising pulleys mounted on the output-shaft, spring meansinterconnecting said pulleys for causing relative rotation therebetweento tighten the cables, together with readily releasable means forlocking the pulleys against relative rotation. The present inventioncomprises an improved structure in which pulleys are mounted on thedrive shaft and are arranged for relative rotation with spring meansprovided to cause such relative rotation whereby the cables may betightened, and readily releasable means are provided for locking thepulleys on the drive shaft against relative rotation. According to thepresent invention the windshield wiper drive apparatus may be installedwith the cable slack and the cables for both Wipers may be tightened bya single operation. If, after a period of service, the cables for anyreason be-- come slack, a single operation will again tighten the cablesfor both wipers.

Referring now more particularly to the embodiment shown in Figs. 1-6 ofthe drawings, the

improved windshield wiper drive apparatus is illustrated as beinginstalled in a vehicle having a two-part windshield including glasspanels l and I separated by a center partition l2. The windshield ispositioned above a dash panel I3, part of which is broken away in Fig. 1in order better to illustrate the windshield wiper drive apparatus. Eachpanel of the windshield is provided with a separate wiper.

On the drivers side of the windshield an output shaft I4 is mounted in abearing and support plate l5 which is secured by bolts Hi to the vehiclebody. The shaft l4 extends outside the body and has an arm l1 mounted onthe end thereof, and a windshield wiper blade I8 is mounted on the armI! in conventional manner. The construction on the passengers side issimilar, a shaft being mounted by means of a plate 2| and carrying atits outer end an arm 22 upon which is mounted a windshield wiper blade23.

A windshield Wiper motor 25, which may be of the conventionalOscillating type, is mounted near the transverse center of the vehicleon the fire wall 26 by means of a bracket 21 which is bolted to the firewall. The bracket 21 has a central aperture aligned with the motor shaft23, and bearing support brackets 29 and 30 are provided to oscillatablysupport a primary drive shaft 3|. The motor shaft 28 carries at its rearend a block 32 forming one part of a universal connection, the otherpart comprising a U-shaped member 33 mounted on the forward end of theprimary drive shaft 3| with its parallel arms adjacent opposite sides ofthe block 32 to provide a simple universal type drive. Bushings 34 and35 support the shaft SI for oscillation in the brackets 29 and 30.

Coupling is made between the primary drive shaft 3| and the output shaft4 by means of a first pair of cables 36a and 36b, these cables passingover idler pulleys designated generally at 31. Similarly, coupling ismade between the primary drive shaft 3| and the second output shaft 20by means of a second pair of cables 38a and 38b which pass over idlerpulleys designated generally at 39. The cables 38a and 381) are crossedto operate the wipers |8 and 23 in opposite directions. If desired theidler pulleys can be dispensed with and the cables may run directly fromthe primary drive shaft 3| to the respective output shafts I4 and 20.

According to the present invention, the conventional rocker arms on thedrive shaft 3| are dispensed with, and the flexible cables are connectedto the drive shaft by means of pulleys mounted on the shaft ashereinafter described. As pointed out earlier, this constructioneliminates movement of the cables in directions transverse to theirlength, thereby minimizing their necessary space for the cables; and theconstruction may also provide an improved cable tensioning means wherebythe cables for both wipers may be tensioned by a single operation.

According to the present invention a first pulley 4D is fixedly mountedon the shaft 3|, preferably being splined to the shaft as illustrated inFig. 3, and having an elongated hub upon which are rotatably mounted asecond pulley 4! and a third pulley 56. Pulley 4D is a double pulley,having an outer peripheral groove 46a and an inner peripheral groove481). One of the cables of one pair, as the cable 35b, is carried in theouter peripheral groove 40a of the pulley 40, this cable being fastenedat its end to an abutment member 4| which is carried in a well 42 in theperiphery of the pulley 43. One cable of the other pair, as the cable38a, is carried in the inner peripheral groove 4% and is fastened at itsend to an abutment member 43 carried in a well 44 in the periphery ofpulley 40.

The second pulley 47 has a peripheral groove 41a in which is carried thecable 36a, said cable being fastened at its end to an abutment member 48which is carried in a well 49 in the periphery of the pulley 41. Ihepulley 47 is provided in one face with a recess 50 which forms a chamber(as shown in Fig. 3) when the pulley 4-1 is position-ed adjacent thepulley 40. A spiral spring 52 is positioned in this chamber, the innerend of the spring being secured to the hub 45 of the pulley 49 and theouter end of the spring being secured to a lug 53 formed by an L-shapedgroove 54 in the peripheral wall of the recess 50.

The third pulley 55 is similar in construction to the pulley 47, and hasa peripheral groove 56a in which the cable 382) is carried, said cablebeing fastened at its end to an abutment member 5'1, carried in a well58. Pulley 56 is provided in one face with a recess 60 which form achamber when pulley 5G is mounted adjacent pulley 47, and a spiralspring 6| is mounted in the chamber, the outer end of the spring beingsecured to a lug 52 and the inner end of the spring being secured to thehub 45. In order to lock the pulleys 48, 4'1 and 56 against relativerotation a pressure member 35 is slidably mounted on the shaft 3|, thispressure member abutting at one end against the inner face of pulley 56as shown best in Fig. 3, and the other end of the pressure memberabutting a nut 68 (Fig. 2) which is threaded onto the shaft 3|. A spring67 and wash-er B'Ea provide a seal where the pressure member 55 extendsthrough the bracket 21.

In order to insure locking against relative rotation, pulley 40 isprovided with a serrated area 63a which mates with a complementaryserrated area 88 on pulley 41, and pulley 41 is provided on its otherface with a serrated area 69 which mates with a complementary serratedarea if] on the adjacent face of pulley 56.

In the operation of the device, the pulleys 41 and 5'6 are rotated inopposite directions in order to wind the respective Springs 52 and 6|and to lengthen the respective cables 36a and 38b. With the parts inthis position the nut 56 is tightened to lock the pulleys againstrelative rotation, and the drive apparatus is installed in the vehicle,leaving the cables slack enough to permit proper positioning and easyassembly of the parts. When the installation is complete, the nut 66 isloosened to permit the springs 52 and BI to unwind partially, rotatingthe pulleys 41 and 56 in opposite directions. The relative rotationbetween pulley 47 and pulley 40 will tighten the cables 36a and 36b, andthe relative rotation between the pulleys 56 and 40 will tighten thecables 38a and 38?). After both cables have been tightened by means ofthis single operation the nut 66 is again tightened to lock the pulleystogether. When the windshield wiper drive apparatus is operated thecables will move only in the direction of their length and there will beno bodily movement of said cables in directions transverse of theirlength as there would be if rocker arms were provided in place of thepulleys on the drive shaft. If, after a period of use, the cables becomeslack for any reason, it is only necessary to loosen the nut 66 and bothcables will autoact-1mm,

matically be tightened as the springs 52 and 6! unwind further.

Figure '7 shows a modified form of the invention. In this form a primarydrive shaft l3l is connected directly to the wiper motor 25, shaft 13!being threaded adjacent both its ends. A first pulley Hill is splined tothe shaft i3l intermediate the ends thereof, pulley l iil having anouter peripheral groove I dim which carries one cable of one pair, asthe cable 35b, and an inner peripheral groove l iilb which carries onecable of the other pair, as the cable 38a. A second pulley I 5? isrotatably mounted on the shaft [3! adjacent one face of the pulley Me,pulleys Mil and id! having complementary recesses in their adjacentfaces. A peripheral groove Idl'a in the pulley it? carries cable 38b,the end of the cable being secured to the pulley in the manner describedabove in connection with Figs. 4-6. A spiral spring 512 is positioned inthe chamber formed by these recesses, one end of the Spring beingsecured to pulley H23 and the other end being secured to pulley Hi1.

A third pulley I55 is rotatably mounted on the shaft i3! adjacent theother face of the pulley Mil. A peripheral groove [Elia in pulley W5carries cable Zita, and the adjacent faces of pulleys l lii and i5?) areprovided with complementary recesses forming a chamber which carries aspiral spring I51, one end of the spring being connected to pulley MBand the other end being connected to pulley E56.

The second and third pulleys i l! and I 5'6 may be rotated with respectto the first pulley use to wind the springs and shorten the cables. NutsH8 and ill are threaded on the shaft adjacent opposite sides of thepulley assembly, and lock washers H2 and F13 are associated respectivelywith said nuts. After the apparatus is installed with the cables slack,one of the nuts may be loosened to permit the springs to unwindpartially to tighten the cables, after which the loose nut may again betightened to lock the pulleys together. Preferably, the adjacent facesof the respective pulleys are provided with complementary serrated areasto prevent relative rotation between the pulleys when they are lockedtogether.

While I have shown and described one embodiment of my invention, it issubject to many modifications. Changes, therefore, in the constructionand arrangement may be made without departing from the spirit and scopeof the invention as set forth in the appended claims.

What is claimed is:

1. In windshield Wiper drive apparatus having drive means with a primarydrive shaft, output shafts for operating wipers on opposite sides ofsaid drive means, and fiexible cable means extending between saidshafts, operating means including: a first pulley mounted on said driveshaft and connected to said cable means; a second pulley mounted on saiddrive shaft and connected to said cable means; a third pulley mounted onsaid drive shaft and connected to said cable means, at least one of saidpulleys being rotatable on said drive shaft; spring means for rotatingat least one of said pulleys relative to the other to tighten said cablemeans; and readily releasable means for locking all said pulleys fixedlyto said drive shaft.

2. In windshield wiper drive apparatus having drive means with a primarydrive shaft, output shafts for operating wipers on opposite sides ofsaid drive means, and flexible cable means extending between saidshafts, operating means in cluding: a first pulley fixedly mounted onsaid drive shaft and connected to said cable means; a second pulleyrotatably mounted on said drive shaft adjacent said first pulley andconnected to said cable means; a third pulley rotatably mounted on saiddrive shaft and connected to said cable means, spring meansinterconnecting said pulleys for causing rotation therebetween totighten said cable means; and readily releasable means for locking saidsecond and third pulleys to said first pulley.

3. Apparatus of the character claimed in claim 2, wherein said pulleyshave complementary serrated areas adapted to engage to lock said pulleystogether, and wherein said locking means comprises a pressure member onsaid drive shaft to hold said members in abutting relation with thecomplementary serrated areas engaged.

4. Apparatus of the character claimed in claim 2, wherein said secondand third pulleys are each provided with a recess forming a chamber, andwherein said spring means comprises a spiral spring positioned in eachchamber.

5. In windshield wiper drive apparatus having drive means with a primarydrive shaft, first and second output shafts for operating wipers onopposite sides of said drive means, and flexible cable means extendingbetween said drive shaft and said first and second output shafts,operating means including: a first pulley mounted on said drive shaftconnected to the cable means extending to said first output shaft; asecond pulley mounted on said drive shaft and connected to the cablemeans extending to said second output shaft; and a third pulley mountedon said drive shaft and connected to cable means extending to both saidfirst and second output shafts.

6. In windshield wiper drive apparatus having drive means with a primarydrive shaft, first and second output shafts for operating wipers onopposite sides of said drive means, and flexible cable means extendingbetween said drive shaft and said first and second output shafts,operating means including: a first pulley mounted on said drive shaftand connected to the cable means extending to said first output shaft; asecond pulley mounted on said drive shaft and connected to the cablemeans extending to said second output shaft, at least one of saidpulleys being rotatable on said drive shaft; a third pulley mounted onsaid drive shaft and connected to cable means extending to both saidfirst and second output shafts; spring means for rotating at least oneof said pulleys relative to the other to tighten said cable means; andreadily releasable means for locking both said pulleys fixedly to saiddrive shaft.

7. In windshield wiper drive apparatus having a motor with a primarydrive shaft, first and second output shafts for operating wipers onopposite sides of said motor, and first and second pairs of flexiblecables extending between said drive shaft and said respective first andsecond output shafts, operating means including: a first pulley fixedlymounted on said drive shaft and connected to one cable of both saidpairs; a second pulley rotatably mounted on said drive shaft andconnected to the other cable of said first pair; a third pulleyrotatably mounted tween to tighten said cables; and readily releasablemeans for locking said pulleys together.

8. Apparatus, of the character claimed in claim 7 wherein said pulleyshave complementary serrated areas adapted to engage to lock sa1d pulleystogether, and wherein said second and third pulleys are provided withrecesses forming chambers, said spring means comprising spiral springspositioned in said respective chambets.

9. In windshield wiper drive apparatus having drive means with a primarydrive shaft, first and second output shafts for operating wipers-onopposite sides of said drive means, and first and second pairs offlexible cables extending between said drive shaft and said respectivefirst and second output shafts, operating means including: a firstpulley fixedly mounted on said drive shaft and connected to one cable ofboth of said pairs, said pulley having an elongated hub; a second pulleyrotatably mounted on said hub and connected to the other cable of saidfirst pair; a third pulley rotatably mounted on said hub and connectedto the other cable of said second pair; spring means connected betweensaid first and second and first and third pulleys for causing rotationtherebetween to tighten said cables; and readily releasable means forlocking said pulleys together.

10. In windshield wiper drive apparatus having a motor with a primarydrive shaft, first and second output shafts for operating wipers onopposite sides of said motor, and first and second pairs of flexiblecables extending between said drive shaft and said respective first andsecond do output shafts, operating means including: a first pulleyfixedly mounted on said drive shaft and connected to one cable of bothof said pairs; a second pulley rotatably mounted on said shaft adjacentone face of said first pulley, said second pulley being connected to theother cable of said first pair and said first and second pulleys havingcomplementary recesses in their adjacent faces; a spiral spring in saidrecesses interconnecting said pulleys for causing rotation therebetweento tighten said first pair of cables; a third pulley rotatably mountedon said shaft adjacent the other face of said first pulley, said thirdpulley being connected to the other cable of said second pair and saidfirst and third pulleys having complementary recesses in their adjacentfaces; a spiral spring in said last mentioned recesses interconnectingsaid first and third pulleys for causing rotation therebetween totighten said second pair of cables; and readily releasable means forlocking said pulleys together.

11. In windshield wiper drive apparatus having drive means with aprimary drive shaft, output shafts for operating wipers on oppositesides of the drive means, and flexible cable means extending betweensaid shafts, operating means including: a first pulley mounted on saiddrive shaft and rotatable therewith and connected to said cable means; asecond pulley rotatably mounted on said drive shaft adjacent said firstpulley and connected to said cable means; a third pulley rotatablymounted on said drive shaft and connected to said cable means, at leastone of said pulleys having a recess forming a chamher with an openingfacing the adjacent pulley; spiral spring means positioned in saidchambers and interconnecting said pulleys for causing rotationtherebetween to tighten said cable means; and readily releasable meansfor locking said second and third pulleys against relative rotation withrespect to said first pulley.

CLARENCE P. MCCLELLAND.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 2,097,928 Konig Nov. 2, 19372,547,285 Rappl Apr. 3, 1951 2,574,504 Sivacek Nov. 13, 1951

